how to compare a gameobject spriterender color

Questions & Answers
1

i have a gameobject with a color and i whant to on mouse down compare if is blue or not

2

The == operator for color will compare the Object reference, not the Color values.

Try to compare either the R, G, & B properties individually or something like

if( String.Equals( renderer.material.color.ToString(), Color.blue.ToString() )) { 
    ... 
}

You may need to add

using System;

to get the .NET String object.